-.TH "LTTNG" "1" "February 9, 2012" "" ""
+.TH "LTTNG" "1" "July 17, 2012" "" ""
.SH "NAME"
lttng \(em LTTng 2.0 tracer control command line tool
involving multiple concurrent processes and threads. Tracing across multiple
systems is also possible.
-The \fBlttng\fP command line tool from lttng-tools package is used to control
+The \fBlttng\fP command line tool from the lttng-tools package is used to control
both kernel and user-space tracing. Every interactions with the tracer should
be done by this tool or by the liblttng-ctl provided with the lttng-tools
package.
LTTng uses a session daemon (lttng-sessiond(8)), acting as a tracing registry,
-which permits you to interact with multiple tracers (kernel and user-space)
+which allows you to interact with multiple tracers (kernel and user-space)
inside the same container, a tracing session. Traces can be gathered from the
kernel and/or instrumented applications (lttng-ust(3)). Aggregating and reading
those traces is done using the babeltrace(1) text viewer.
+We introduce the notion of \fBtracing domains\fP which is essentially a type of
+tracer (kernel or user space for now). In the future, we could see a third
+tracer being for instance an hypervisor. For some commands, you'll need to
+specify on which domain the command applies (-u or -k). For instance, enabling
+a kernel event, you must specify the kernel domain to the command so we know
+for which tracer this event is for.
+
In order to trace the kernel, the session daemon needs to be running as root.
LTTng provides the use of a \fBtracing group\fP (default: tracing). Whomever is
in that group can interact with the root session daemon and thus trace the
kernel. Session daemons can co-exist meaning that you can have a session daemon
-running as Alice that can be use to trace her applications along side with a
-root daemon or even a Bob daemon. We highly recommand to start the session
+running as Alice that can be used to trace her applications along side with a
+root daemon or even a Bob daemon. We highly recommend to start the session
daemon at boot time for stable and long term tracing.
Every user-space applications instrumented with lttng-ust(3), will
.PP
.TP
-.BR "-h, --help"
+.BR "\-h, \-\-help"
Show summary of possible options and commands.
.TP
-.BR "-v, --verbose"
+.BR "\-v, \-\-verbose"
Increase verbosity.
-FIXME : details (-v : sessiond verbose, -vv : consumerd verbose, etc) ?
+Three levels of verbosity are available which are triggered by putting additional v to
+the option (\-vv or \-vvv)
.TP
-.BR "-q, --quiet"
+.BR "\-q, \-\-quiet"
Suppress all messages (even errors).
.TP
-.BR "-g, --group NAME"
+.BR "\-g, \-\-group NAME"
Set unix tracing group name. (default: tracing)
.TP
-.BR "-n, --no-sessiond"
+.BR "\-n, \-\-no-sessiond"
Don't automatically spawn a session daemon.
.TP
-.BR "--sessiond-path"
+.BR "\-\-sessiond\-path"
Set session daemon full binary path.
.TP
-.BR "--list-options"
+.BR "\-\-list\-options"
Simple listing of lttng options.
.TP
-.BR "--list-commands"
+.BR "\-\-list\-commands"
Simple listing of lttng commands.
.SH "COMMANDS"
counters (hardware branch misses and cache misses), to all events in the trace
data output:
-# lttng add-context -k -t prio -t perf:branch-misses -t perf:cache-misses
+# lttng add-context \-k \-t prio \-t perf:branch-misses \-t perf:cache-misses
-Please take a look at the help (-h/--help) for a detailed list of available
+Please take a look at the help (\-h/\-\-help) for a detailed list of available
contexts.
-If no channel and no event is given (-c/-e), the context is added to all
+If no channel and no event is given (\-c/\-e), the context is added to all
channels (which applies automatically to all events in that channel). Otherwise
-the context will be added only to the channel (-c) and/or event (-e) indicated.
+the context will be added only to the channel (\-c) and/or event (\-e) indicated.
-If \fB-s, --session\fP is omitted, the session name is taken from the .lttngrc
+If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
file.
.fi
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
--s, --session NAME
+\-s, \-\-session NAME
Apply on session name.
--c, --channel NAME
+\-c, \-\-channel NAME
Apply on channel name.
--e, --event NAME
+\-e, \-\-event NAME
Apply on event name.
--k, --kernel
+\-k, \-\-kernel
Apply for the kernel tracer
--u, --userspace
+\-u, \-\-userspace
Apply for the user-space tracer
--t, --type TYPE
+\-t, \-\-type TYPE
Context type. You can repeat this option on the command line. Please
- use "lttng add-context -h" to list all available types.
+ use "lttng add-context \-h" to list all available types.
.fi
.IP
This sequence of commands will gather a trace executing a kretprobe hooked on
an empty function, gathering PMU counters LLC (Last Level Cache) misses
-information (see lttng add-context --help to see the list of available PMU
+information (see lttng add-context \-\-help to see the list of available PMU
counters).
# lttng create calibrate-function
-# lttng enable-event calibrate --kernel --function lttng_calibrate_kretprobe
-# lttng add-context --kernel -t perf:LLC-load-misses -t perf:LLC-store-misses \\
- -t perf:LLC-prefetch-misses
+# lttng enable-event calibrate \-\-kernel \-\-function lttng_calibrate_kretprobe
+# lttng add-context \-\-kernel \-t perf:LLC-load-misses \-t perf:LLC-store-misses \\
+ \-t perf:LLC-prefetch-misses
# lttng start
# for a in $(seq 1 10); do \\
- lttng calibrate --kernel --function;
+ lttng calibrate \-\-kernel \-\-function;
done
# lttng destroy
-# babeltrace $(ls -1drt ~/lttng-traces/calibrate-function-* | tail -n 1)
+# babeltrace $(ls \-1drt ~/lttng-traces/calibrate-function-* | tail \-n 1)
The output from babeltrace can be saved to a text file and opened in a
spreadsheet (e.g. oocalc) to focus on the per-PMU counter delta between
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
--k, --kernel
+\-k, \-\-kernel
Apply for the kernel tracer
--u, --userspace
+\-u, \-\-userspace
Apply for the user-space tracer
---function
+\-\-function
Dynamic function entry/return probe (default)
.fi
.IP
-.IP "\fBcreate\fP [OPTIONS] [NAME]
+.IP "\fBcreate\fP [NAME] [OPTIONS]
.nf
Create tracing session.
On creation, a \fB.lttngrc\fP file is created in your $HOME directory
containing the current session name. If NAME is omitted, a session name is
-automatically created having this form: 'auto-yyyymmdd-hhmms'.
+automatically created having this form: 'auto-yyyymmdd-hhmmss'.
-If no \fB-o, --output\fP is specified, the traces will be written in
+If no \fB\-o, \-\-output\fP is specified, the traces will be written in
$HOME/lttng-traces.
.fi
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-\-list-options
Simple listing of options
--o, --output PATH
+\-o, \-\-output PATH
Specify output path for traces
+
+Using these options, each API call can be controlled individually. For
+instance, \-C does not enable the consumer automatically. You'll need the \-e
+option for that.
+
+\-U, \-\-set-uri=URL
+ Set URL for the enable-consumer destination. It is persistent for the
+ session lifetime. Redo the command to change it. This will set both
+ data and control URL for network.
+\-C, \-\-ctrl-url=URL
+ Set control path URL. (Must use -D also)
+\-D, \-\-data-url=URL
+ Set data path URL. (Must use -C also)
+ \-\-no-consumer
+ Don't activate a consumer for this session.
+ \-\-disable-consumer
+ Disable consumer for this session.
+
+See \fBenable-consumer\fP command below for the supported URL format.
+
+.B EXAMPLES:
+
+# lttng create -U net://192.168.1.42
+Uses TCP and default ports for the given destination.
+
+# lttng create -U net6://[fe80::f66d:4ff:fe53:d220]
+Uses TCP, default ports and IPv6.
+
+# lttng create s1 -U net://myhost.com:3229
+Create session s1 and set its consumer to myhost.com on port 3229 for control.
.fi
.IP
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-a, \-\-all
+ Destroy all sessions
+\-\-list-options
Simple listing of options
.fi
.nf
Enable tracing channel
-If \fB-s, --session\fP is omitted, the session name is taken from the .lttngrc
+To enable event, you must first enable a channel which contains event(s).
+
+If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
file.
.fi
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show this help
---list-options
+\-\-list-options
Simple listing of options
--s, --session
+\-s, \-\-session
Apply on session name
--k, --kernel
+\-k, \-\-kernel
Apply to the kernel tracer
--u, --userspace
+\-u, \-\-userspace
Apply to the user-space tracer
---discard
+\-\-discard
Discard event when subbuffers are full (default)
---overwrite
+\-\-overwrite
Flight recorder mode : overwrites events when subbuffers are full
---subbuf-size
+\-\-subbuf-size
Subbuffer size in bytes (default: 4096, kernel default: 262144)
---num-subbuf
- Number of subbufers (default: 8, kernel default: 4)
---switch-timer
+\-\-num-subbuf
+ Number of subbuffers (default: 4)
+ Needs to be a power of 2 for kernel and ust tracers
+\-\-switch-timer
Switch subbuffer timer interval in usec (default: 0)
---read-timer
+ Needs to be a power of 2 for kernel and ust tracers
+\-\-read-timer
Read timer interval in usec (default: 200)
.fi
.IP
+.IP "\fBenable-consumer\fP [-u|-k] [URL] [OPTIONS]"
+.nf
+Enable a consumer for the tracing session and domain.
+
+By default, every tracing session has a consumer attached to it using the local
+filesystem as output. The trace is written in $HOME/lttng-traces. This command
+allows the user to specify a specific URL after the session was created for a
+specific domain. If no domain is specified, the consumer is applied on all
+domains.
+
+Without options, the behavior is to enable a consumer to the current URL. The
+default URL is the local filesystem at the path of the session mentioned above.
+
+The enable-consumer feature supports both local and network transport. You must
+have a running \fBlttng-relayd(8)\fP for network transmission or any other daemon
+that can understand the streaming protocol of LTTng.
+.fi
+
+.B OPTIONS:
+
+.nf
+\-h, \-\-help
+ Show summary of possible options and commands.
+\-\-list-options
+ Simple listing of options
+\-s, \-\-session
+ Apply on session name
+\-k, \-\-kernel
+ Apply for the kernel tracer
+\-u, \-\-userspace
+ Apply for the user-space tracer
+
+Using these options, each API call can be controlled individually. For
+instance, \-C does not enable the consumer automatically. You'll need the \-e
+option for that.
+
+\-U, \-\-set-uri=URL
+ Set URL for the enable-consumer destination. It is persistent for the
+ session lifetime. Redo the command to change it. This will set both
+ data and control URL for network.
+\-C, \-\-ctrl-url=URL
+ Set control path URL. (Must use -D also)
+\-D, \-\-data-url=URL
+ Set data path URL. (Must use -C also)
+\-e, \-\-enable
+ Enable consumer
+
+.B URL FORMAT:
+
+proto://[HOST|IP][:PORT1[:PORT2]][/TRACE_PATH]
+
+Supported protocols are (proto):
+> file://...
+ Local filesystem full path.
+
+> net[6]://...
+ This will use the default network transport layer which is TCP for both
+ control (PORT1) and data port (PORT2). The default ports are
+ respectively 5342 and 5343.
+
+> tcp[6]://...
+ Can only be used with -C and -D together
+
+NOTE: IPv6 address MUST be enclosed in brackets '[]' (rfc2732)
+
+.B EXAMPLES:
+
+$ lttng enable-consumer -u net://192.168.1.42
+
+Uses TCP and default ports for user space tracing (-u) where the IP address
+above is the destination machine where the traces will be streamed and a
+\fBlttng-relayd(8)\fP is listening.
+.fi
+
.IP "\fBenable-event\fP NAME[,NAME2,...] [-k|-u] [OPTIONS]"
.nf
Enable tracing event
-A tracing event is always assigned to a channel. If \fB-c, --channel\fP is
+A tracing event is always assigned to a channel. If \fB\-c, \-\-channel\fP is
omitted, a default channel named '\fBchannel0\fP' is created and the event is
-added to it. For the user-space tracer, using \fB-a, --all\fP is the same as
+added to it. For the user-space tracer, using \fB\-a, \-\-all\fP is the same as
using the wildcard "*".
-If \fB-s, --session\fP is omitted, the session name is taken from the .lttngrc
+If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
file.
.fi
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-\-list-options
Simple listing of options
--s, --session
+\-s, \-\-session
Apply on session name
--c, --channel
+\-c, \-\-channel
Apply on channel name
--a, --all
- Enable all tracepoints
--k, --kernel
+\-a, \-\-all
+ Enable all tracepoints and syscalls
+\-k, \-\-kernel
Apply for the kernel tracer
--u, --userspace
+\-u, \-\-userspace
Apply for the user-space tracer
---tracepoint
+\-\-tracepoint
Tracepoint event (default)
- userspace tracer supports wildcards at end of string. Don't forget to
quote to deal with bash expansion.
e.g.:
"*"
"app_component:na*"
---loglevel
+\-\-loglevel
Tracepoint loglevel
---probe [addr | symbol | symbol+offset]
+\-\-probe [addr | symbol | symbol+offset]
Dynamic probe. Addr and offset can be octal (0NNN...), decimal (NNN...)
or hexadecimal (0xNNN...)
---function [addr | symbol | symbol+offset]
+\-\-function [addr | symbol | symbol+offset]
Dynamic function entry/return probe. Addr and offset can be octal
(0NNN...), decimal (NNN...) or hexadecimal (0xNNN...)
---syscall
- System call event
- Enabling syscalls tracing (kernel tracer), you will not be able to disable them
- with disable-event. This is a known limitation. You can disable the entire
- channel to do the trick.
+\-\-syscall
+ System call event. Enabling syscalls tracing (kernel tracer), you will
+ not be able to disable them with disable-event. This is a known
+ limitation. You can disable the entire channel to do the trick.
+
+\-\-filter 'expression'
+ Set a filter on a newly enabled event. Filter expression on event
+ fields, event recording depends on evaluation. Only specify on first
+ activation of a given event within a session. Filter only allowed when
+ enabling events within a session before tracing is started. If the
+ filter fails to link with the event within the traced domain, the event
+ will be discarded. Currently, filter is only implemented for the
+ user-space tracer.
+
+ Expression examples:
+
+ 'intfield > 500 && intfield < 503'
+ '(stringfield == "test" || intfield != 10) && intfield > 33'
+ 'doublefield > 1.1 && intfield < 5.3'
+
+ Wildcards are allowed at the end of strings:
+ 'seqfield1 == "te*"'
+ In string literals, the escape character is a '\\'. Use '\\*' for
+ the '*' character, and '\\\\' for the '\\' character.
.fi
-.IP "\fBdisable-channel\fP NAME[,NAME2,...] [-k|-u] [OPTIONS]"
+.IP "\fBdisable-channel\fP NAME[,NAME2,...] [\-k|\-u] [OPTIONS]"
.nf
Disable tracing channel
Disabling a channel makes all event(s) in that channel to stop tracing. You can
enable it back by calling \fBlttng enable-channel NAME\fP again.
-If \fB-s, --session\fP is omitted, the session name is taken from the .lttngrc
+If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
file.
.fi
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
+ Show summary of possible options and commands.
+\-\-list-options
+ Simple listing of options
+\-s, \-\-session NAME
+ Apply on session name
+\-k, \-\-kernel
+ Apply for the kernel tracer
+\-u, \-\-userspace
+ Apply for the user-space tracer
+.fi
+
+.IP "\fBdisable-consumer\fP [\-k|\-u] [OPTIONS]"
+.nf
+Disable the consumer of a tracing session.
+
+This call MUST be done BEFORE tracing has started.
+.fi
+
+.B OPTIONS:
+
+.nf
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-\-list-options
Simple listing of options
--s, --session
+\-s, \-\-session NAME
Apply on session name
--k, --kernel
+\-k, \-\-kernel
Apply for the kernel tracer
--u, --userspace
+\-u, \-\-userspace
Apply for the user-space tracer
.fi
-.IP "\fBdisable-event\fP NAME[,NAME2,...] [-k|-u] [OPTIONS]"
+.IP "\fBdisable-event\fP NAME[,NAME2,...] [\-k|\-u] [OPTIONS]"
.nf
Disable tracing event
The event, once disabled, can be re-enabled by calling \fBlttng enable-event
NAME\fP again.
-If \fB-s, --session\fP is omitted, the session name is taken from the .lttngrc
+If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
file.
.fi
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-\-list-options
Simple listing of options
--s, --session
+\-s, \-\-session
Apply on session name
--k, --kernel
+\-k, \-\-kernel
Apply for the kernel tracer
--u, --userspace
+\-u, \-\-userspace
Apply for the user-space tracer
.fi
-.IP "\fBlist\fP [-k|-u] [SESSION [SESSION_OPTIONS]]"
+.IP "\fBlist\fP [\-k|\-u] [SESSION [SESSION_OPTIONS]]"
.nf
-List tracing session informations.
+List tracing session information.
With no arguments, it will list available tracing session(s).
-With -k alone, it will list all available kernel events (except the system
+With the session name, it will display the details of the session including
+the trace file path, the associated channels and their state (activated
+and deactivated), the activated events and more.
+
+With \-k alone, it will list all available kernel events (except the system
calls events).
-With -u alone, it will list all available user-space events from registered
-applications. Here is an example of 'lttng list -u':
+With \-u alone, it will list all available user-space events from registered
+applications. Here is an example of 'lttng list \-u':
PID: 7448 - Name: /tmp/lttng-ust/tests/hello/.libs/lt-hello
ust_tests_hello:tptest_sighandler (type: tracepoint)
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-\-list-options
Simple listing of options
--k, --kernel
- Select kernel domain (FIXME : apparition de la notion de "domain" ici)
--u, --userspace
+\-k, \-\-kernel
+ Select kernel domain
+\-u, \-\-userspace
Select user-space domain.
-Session options:
--c, --channel NAME
+.B SESSION OPTIONS:
+
+\-c, \-\-channel NAME
List details of a channel
--d, --domain
+\-d, \-\-domain
List available domain(s)
.fi
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-\-list-options
Simple listing of options
.fi
.IP
-.IP "\fBstart\fP [OPTIONS] [NAME]"
+.IP "\fBstart\fP [NAME] [OPTIONS]"
.nf
Start tracing
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-\-list-options
Simple listing of options
.fi
.IP
-.IP "\fBstop\fP [OPTIONS] [NAME]"
+.IP "\fBstop\fP [NAME] [OPTIONS]"
.nf
Stop tracing
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-\-list-options
Simple listing of options
.fi
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-\-list-options
Simple listing of options
.fi
By default, the babeltrace viewer will be used for text viewing.
-The SESSION_NAME is an optional session name. If not specified, lttng will get
-it from the configuration file (.lttngrc).
+If SESSION_NAME is omitted, the session name is taken from the .lttngrc file.
+
.fi
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show this help
---list-options
+\-\-list-options
Simple listing of options
--t, --trace-path PATH
+\-t, \-\-trace-path PATH
Trace directory path for the viewer
--e, --viewer CMD
+\-e, \-\-viewer CMD
Specify viewer and/or options to use
This will completely override the default viewers so
please make sure to specify the full command. The trace
to the arguments
.fi
+.SH "EXIT VALUES"
+On success 0 is returned and a positive value on error. Value of 1 means a command
+error, 2 an undefined command, 3 a fatal error and 4 a command warning meaning that
+something went wrong during the command.
+
+Any other value above 10, please refer to
+.BR <lttng/lttng-error.h>
+for a detailed list or use lttng_strerror() to get a human readable string of
+the error code.
+
+.PP
.SH "ENVIRONMENT VARIABLES"
.PP
.PP
.PP
-.IP "LTTNG_SESSIOND_PATH_ENV"
-Allows to specify the full session daemon binary path to lttng command line
-tool. You can also use --sessiond-path option having the same effect.
+.IP "LTTNG_SESSIOND_PATH"
+Allows one to specify the full session daemon binary path to lttng command line
+tool. You can also use \-\-sessiond-path option having the same effect.
.SH "SEE ALSO"
-
-.PP
-babeltrace(1), lttng-ust(3), lttng-sessiond(8)
-.PP
+.BR babeltrace(1),
+.BR lttng-ust(3),
+.BR lttng-sessiond(8),
+.BR lttng-relayd(8),
+.BR lttng-health-check(3)
.SH "BUGS"
-.PP
-No show stopper bugs known yet at this stable version.
+With version 2.1 and earlier, if you start a tracing session and than enable
+kernel events, they are not recorded and the tracing session fails to stop. To
+fix this, simply enable events before starting the session.
If you encounter any issues or usability problem, please report it on our
-mailing list <lttng-dev@lists.lttng.org> to help improve this project.
+mailing list <lttng-dev@lists.lttng.org> to help improve this project or
+at https://bugs.lttng.org which is a bugtracker.
.SH "CREDITS"
.PP
-lttng is distributed under the GNU public license version 2. See the file
+lttng is distributed under the GNU General Public License version 2. See the file
COPYING for details.
.PP
A Web site is available at http://lttng.org for more information on the LTTng
.PP
Thanks to Yannick Brosseau without whom this project would never have been so
lean and mean! Also thanks to the Ericsson teams working on tracing which
-helped us greatly with detailled bug reports and unusual test cases.
+helped us greatly with detailed bug reports and unusual test cases.
Thanks to our beloved packager Alexandre Montplaisir-Goncalves (Ubuntu and PPA
maintainer) and Jon Bernard for our Debian packages.
Special thanks to Michel Dagenais and the DORSAL laboratory at Polytechnique de
Montreal for the LTTng journey.
-.pp
+.PP
.SH "AUTHORS"
.PP
projects / lttng-tools.git / blobdiff